Sensor and guide wire assemblies in which a sensor is mounted at the distal end of a guide wire are known. In U.S. Pat. Re. 35,648, which is assigned to the present assignee, an example of such a sensor and guide wire assembly is disclosed, where a sensor guide comprises a sensor element, an electronic unit, a signal transmitting cable connecting the sensor element to the electronic unit, a flexible tube having the cable and the sensor element disposed therein, a solid metal wire, and a coil attached to the distal end of the solid wire. The sensor element comprises a pressure sensitive device, e.g. a membrane, with piezoresistive elements connected in a Wheatstone bridge-type of arrangement mounted thereon.
As is disclosed in, for example, U.S. Pat. No. 6,167,763, which also is assigned to the present assignee, the sensor element can be arranged inside a short tube (also referred to as a sleeve or jacket), which protects the sensor element and comprises an aperture through which the pressure sensitive device is in contact with the ambient medium. The U.S. Pat. No. 6,167,763 illustrates further that a first coil can be attached to the distal end of the jacket and that a similar second coil can be attached to the proximal end of the jacket. The solid metal wire—which in the art usually is referred to as the core wire—extends through the interior of the jacket and can be provided with an enlarged diameter portion adapted for mounting of the sensor element. The first and second coils are attached to the respective end of the jacket by gluing, or alternatively soldering. Glue or solder is also used to fixate the jacket to the core wire.
A principally different way of attaching a coil to a sleeve, which accommodates a sensor element, is disclosed in the U.S. Pat. No. 5,715,827 assigned to Cardiometrics, Inc. Here a portion of the outer mantle surface of the sleeve is provided with helical grooves in such a way that the coil can be screwed onto the sleeve. If needed, the coil can then be glued or soldered to the sleeve mantle. Although sensor and guide wire assemblies comprising a jacket designed according to the techniques presented herein in practise have proven to work very well, the design and attachment functionality of such a jacket can be improved, not least from a manufacturing point of view.